It's hard to believe that it's been five years since the original Gears of War released on Xbox 360, less than a year after the console's release. And while the series has certainly matured over the years in a number of ways, it hasn't necessarily undergone any sort of massive reinvention, either. But that's not entirely a negative thing.
Instead of crow-barring in changes to the formula where they don't belong, Epic Games' has kept their sci-fi franchise fresh and interesting by gradually introducing new features, ideas, and enhancements that build on the core Gears experience. In doing so, they've preserved the essence of what's made their brand of cover-based combat so revered, while not making it feel like just a lazy sequel.